fix

app/Http/Requests/Admin/ConfigSave.php

@@ -16,8 +16,8 @@ class ConfigSave extends FormRequest
         'email_verify' => 'in:0,1',
         'app_name' => '',
         'app_description' => '',
-        'app_url' => 'url',
-        'subscribe_url' => 'url',
+        'app_url' => 'nullable|url',
+        'subscribe_url' => 'nullable|url',
         'try_out_enable' => 'in:0,1',
         'try_out_plan_id' => 'integer',
         'try_out_hour' => 'numeric',